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Paraffin heater for a greenhouse

Updated: 21 October 2026

The allotment greenhouse has no socket, the forecast is a clear night, and you want the frost off a small house rather than a living-room temperature. A paraffin heater for a greenhouse is the Royal Horticultural Society’s route when there is no electricity, with the vents open, for plants that tolerate low temperatures. In this amazon.co.uk set the worked example is the Trendi E-SP100. Camping stoves and the Corona cabinet stay on the [paraffin heater comparison](/hub/portable-heaters/paraffin-heater). Lighting steps stay on [how to use a paraffin heater](/hub/portable-heaters/paraffin-heater/sub/paraffin-heater-how-to-use). Peter F. used the RHS, Two Wests, and the Trendi’s amazon.co.uk reviews on 19 October 2026. He did not measure a greenhouse. A qualifying purchase can earn a commission at no extra cost to you.

The allotment greenhouse has no socket, the forecast is a clear night, and you want the frost off a small house rather than a living-room temperature.

Our top picks

PFCTART PFCTART YMHW00084 5 L

Best overall

PFCTART PFCTART YMHW00084 5 L
6.6/10about £89.99
View offer
Tecno Air System Corona RX 2485 (Tecno Air System)

Rank 2

Tecno Air System Corona RX 2485 (Tecno Air System)
8.2/10about £189
View offer
Trendi Trendi E-SP100 4.5 L

Best value

Trendi Trendi E-SP100 4.5 L
7.0/10about £18.95
View offer
On this page
  1. 1.When a paraffin heater belongs in the greenhouse
  2. 2.The heater in this set
  3. 3.Plants, water, and ethylene
  4. 4.Clearance and overnight

When a paraffin heater belongs in the greenhouse

It belongs where you cannot run a proper electric supply and you only need the edge off a frost. The RHS says paraffin or gas is the option without electricity, and an electric fan or tube heater is the option when you have a supply and you want a thermostat. A wick heater has no thermostat. Two Wests limit paraffin to a remote site such as an allotment, at least 30 cm from anything that can burn. Combustion puts water, ethylene, and carbon monoxide into the house. The RHS says ventilate, and it points the method at plants that tolerate quite low temperatures, H2 or hardier. If a socket is already on the staging, this category is the wrong buy even at £18.95. Fuel grade, C1 rather than C2, is on the buying guide before you fill anything.

The heater in this set

The Trendi E-SP100 is £18.95, with a 4.5 litre tank. The bullets claim up to 80 hours and a 6x8 greenhouse. Across 577 amazon.co.uk reviews it sits at 3.7. Those reviews also repeat loose screws and leaks, and one chimney fell off while alight. The heat field says 4500 W and the coverage field says 0.0307 m². Neither matches the 6x8 bullet. Two Wests describe their own 4.5 litre heater at about 300 W. That is their heater. Greenhouse People claim a flame-extinguishing device on a different heater at £39. The Trendi listing does not state a shut-off. Do not move that claim across.
PFCTART PFCTART YMHW00084 5 L

Testsieger

PFCTART PFCTART YMHW00084 5 L
6.6/10about £89.99
View offer

Plants, water, and ethylene

The RHS names water, ethylene, and carbon monoxide as what the flame adds to the air. Knowsley Council’s rule of thumb is about a gallon of water for each gallon of paraffin burned. On a small house that moisture sits on the glass unless a vent is open. Two Wests say orchids and cacti are a poor fit because of fumes. The RHS method is for H2 or hardier plants, not for seedlings next to the chimney. Black soot on leaves means the wick was high, the chimney was off its seat, or the fuel was wrong. A paraffin smell is not a carbon monoxide detector. The human limit is on the indoor safety page.

Clearance and overnight

Two Wests’ 30 cm is the clearance from glazing bars, fleece, and dry staging. A metre is London Fire Brigade’s distance for you while you are in the house. If the chimney screws do not hold, do not light it. Several buyers only trusted the lamp after they fitted their own nuts and bolts. Overnight is a frost watch with the vent open, the heater level, and the chimney fixed. This page does not promise that a 6x8 stays above freezing. The 6x4 review at about 1.7 °C was one cold night. If you need a named temperature, wait until you can fit an electric heater with a thermostat. If the screws will not lock tonight, leave the heater cold.

Common questions

Can I use one if the greenhouse has electricity?
You can, and you give up the reason most people buy one. The Royal Horticultural Society points to an electric fan or tube heater when you have a proper supply and you want a thermostat. A wick heater cannot hold a set temperature. If the socket is already there, the paraffin lamp is the weaker tool, even at £18.95.
Why did my plants go black with soot?
The wick was high, the chimney was not seated, or the fuel was not Class C1 paraffin. Two Wests say a long wick makes black smoke on this class of heater. Soot on leaves is a stop signal, not a mark you wipe off and ignore. Extinguish the heater, let it cool, and fix the chimney or the fuel before you light it again.
Are orchids or seedlings safe next to it?
Two Wests say orchids and cacti are a poor fit because of fumes and raised carbon dioxide. The RHS limits paraffin heating to plants that tolerate low temperatures, H2 or hardier, because the flame adds water, ethylene, and carbon monoxide. Seedlings you are trying to push on are the wrong neighbours for an unflued lamp. Hardy stock and an open vent are the case the method is written for.
Does the Trendi have a flame extinguisher?
The listing does not state one. Greenhouse People claim a flame-extinguishing device on a different single-burner heater at £39. That claim does not transfer to the Trendi E-SP100. Reviews of the Trendi talk about screws, soot, and a chimney that came off while alight. Treat shut-off as not stated.
Should I leave it on all night?
Only as a frost watch: chimney fixed, heater level, vent open, and plants that can take a low temperature. It is not a thermostat you can forget. Knowsley Council’s rule of thumb is about a gallon of water for each gallon of fuel, so a sealed house wets the glass. If the screws will not hold, leave it cold.

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Sources

Public UK sources on carbon monoxide, unflued heaters, kerosene and greenhouse heating. Listing prices, stars, and review counts are from amazon.co.uk on 19 October 2026.

  1. NHS — Carbon monoxide poisoning (retrieved 19 October 2026)
  2. Oil Heaters (Safety) Regulations 1977 (retrieved 19 October 2026)
  3. GOV.UK — General Product Safety Regulations 2005 (retrieved 19 October 2026)
  4. GOV.UK — Kerosene: general information (retrieved 19 October 2026)
  5. London Fire Brigade — Portable heaters, gas fires and open fires (retrieved 19 October 2026)
  6. RHS — Heating greenhouses efficiently (retrieved 19 October 2026)
  7. NWF Fuels — Kerosene FAQs (retrieved 19 October 2026)
  8. Dry-it-Out — Corona RX2485 seller description (retrieved 19 October 2026)